When you use the Dwolla white label ACH payout API, "there are no individual transaction fees or percentages—regardless of how many times you, your business, or your application transfers money". Providing a pretty interesting alternative to the common, pay for what you use business model used by man API providers today.

I predict this approach to API deployment will become more common place in coming years. Many developers, and API consumers will be quite content just calling your regular retail API, but more specialty, and larger partners are going to want the functionality you offer, but are not going to want to be metered for each API transaction.

When I deploy wholesale, or white label versions of my APIs I will not be charging for each API call, however I will still be managing API access, and usage with my 3Scale API infrastructure, because I still want to be able to get analytics, and other awareness generated via my API management layer. The cost of each wholesale API installation will depend on the scope of the instance, whether it is in our infrastructure, or yours, and how much ownership me and my APIware team will have in API operations.